高非线性光子晶体光纤

用有效折射率方法,设计了掺钛蓝宝石（Ti ：sapphire）飞秒激光器工作波长0．800μm附近的高非线性光子晶体光纤。     

一种近红外波段的高双折射高非线性光子晶体光纤

提出了一种具有中心缺陷孔的新型非对称椭圆光子晶体光纤,采用全矢量有限元法研究了其双折射、色散和非线性等特性。通过改变第一层椭圆孔的角度,加强了结构的双折射性能,同时还能改善结构的色散表现。分析计算结果得出,设计合适的结构参数可在波长1.55μm处获得3.05×10~(-2)的高双折射,同时在X和Y偏振方向获得较高非线性系数。此外,在保持高双折射的同时,此PCF也可获得1 000~1 550 nm近550 nm的负色散平坦区。该新型近红外波段的高双折射高非线性负平坦色散的光子晶体光纤在偏振控制、非线性光学及光纤通信等领域具有广泛的应用前景。     

高非线性平坦色散光子晶体光纤的研究

为了研究最内层空气孔的大小以及空气孔的占空比改变对光子晶体光纤的非线性系数、色散的影响,采用全矢量有限元方法,进行了理论分析和实验验证,取得了非线性系数、色散系数随频率和结构参量的变化数据。结果表明,三角晶格结构的非线性系数大,色散较平坦,能够在400nm~1160nm保持单模传输,非线性系数达到172km-1·W-1,在0.65μm~1.0μm范围内具有超平坦色散。这一结果对光通信领域的研究是有帮助的。     

方形空芯光子晶体光纤的特性分析

利用全矢量有限元法,分析了方形空芯光子晶体光纤的色散特性、纤芯内的能量分布和有效模面积.结果表明,方形空芯光子晶体光纤在1.67～1.81 μm范围内具有较平坦的色散特性,较高的能量分布和较大的有效模面积,为进一步设计具有平坦色散和大模场面积的方形空芯光子晶体光纤提供了理论依据和参考.     

一种新型高双折射光子晶体光纤的特性研究

设计了一种新型结构的光子晶体光纤,建立了对应的数学模型并采用全矢量有限元法对该结构的模场强度、有效折射率、双折射、色散特性和限制损耗进行了分析。研究表明,该光纤在1 550nm处可以获得高达7.66×10-3的双折射和低至12ps/(nm·km)的色散值,同时在800～1 600nm波长范围内,始终保持1.498×10-6 dB/m以下的极低限制损耗,可用于制造极低色散值的保偏光纤。     

高非线性光子晶体光纤的研制

报道了一种自行研制的高非线性光子晶体光纤,介绍了其结构设计及制备工艺.该光子晶体光纤外包层直径为125.8μm,芯径为2.9μm,孔径/芯径之比为0.67.在波长为800nm飞秒激光输入下,其产生的连续光谱范围为450-1400nm.     

高非线性色散平坦光子晶体光纤的理论研究

为了研究光子晶体光纤结构参数对非线性系数及色散特性的影响,采用全矢量等效折射率模型,进行了理论分析,研究发现,通过调节结构参数可以灵活设计波长在820nm附近具有较大非线性系数和较低色散值的高非线性色散平坦光子晶体光纤。结果表明,高非线性色散平坦光子晶体光纤的研究前景十分可观。     

光子晶体光纤色散补偿特性和非线性系数的研究

利用全矢量等效折射率模型计算了光子晶体光纤结构参数对非线性系数及色散特性的影响,研究发现通过调节结构参数可以灵活设计波长在1.55 μm附近具有高色散值、负色散斜率、低非线性系数的色散补偿型光纤,数值模拟和分析表明光子晶体光纤应用于色散补偿型光纤的研究前景十分可观.     

光子晶体光纤的非线性特性研究

较全面地介绍了有关光子晶体光纤非线性特性最新的理论和实验进展,其中包括关于两种基本类型的光子晶体光纤非线性特性的各种实验现象及理论分析,并探讨了基于非线性特性的全光纤器件的广阔应用前景。     

Design for photonic crystal fibers with high nonlinearity and flattened dispersion for self-frequency shift of Raman soliton

A new concept of photonic crystal fiber (PCF) with high nonlinearity and flattened dispersion was designed. The PCF structure is indeed a hexagon lattice. The bigger air holes in the outer rings are used to confine the light field into the core region for enhancing the nonlinearity. The flattened dispersion can be achieved by adjusting the diameters of six smaller air holes in the first ring, and six micro air holes are inserted between smaller air holes for higher nonlinearity and the better flattened dispersion. By optimizing the size of the smaller and micro holes, the PCF can reach to high nonlinearity of 23.3 W⁻¹ · km⁻¹ and the low dispersion of 51.32 ps/(nm·km) with the fluctuation range of 0.98 ps/(nm·km), which is within the wavelength range of 1 400 nm to 1 900 nm. The designed PCF can be used in important applications in realizing the Raman soliton self-frequency shift (RSSFS).     

Ultra-flattened chromatic dispersion and highly nonlinear photonic crystal fibers with ultralow confinement loss employing hybrid cladding

In this paper, two new types of dispersion-flattened photonic crystal fibers (DF-PCFs) with highly nonlinear and ultralow confinement loss are proposed. These new PCF structures adopt hybrid cladding with different air-holes diameters, pitches and air-holes arranged fashions. In order to analyze the proposed PCFs, the full-vector finite element method with anisotropic perfectly matched layers has been used. Results show that the ultra-flattened dispersion of 0.931 ps/(nm km) (DF-PCF1) and 1.533 ps/(nm km) (DF-PCF2) can be achieved in the wavelength range from 1.3 to 1.6 μm with confinement losses lower than 0.001 dB/km in the same wavelength range. Meanwhile, the nonlinear coefficients of our proposed PCFs are greater than 23.83 W⁻¹ km⁻¹ (DF-PCF1) and 29.65 W⁻¹ km⁻¹ (DF-PCF2) at the wavelength of 1.55 μm, and two near-zero dispersion values of 0.328 ps/(nm km) (DF-PCF1) and −0.015 ps/(nm km) (DF-PCF2) can also be obtained at the same wavelength. Furthermore, the influence of manufacturing imperfections of parameters on dispersion and nonlinearity is discussed to verify the robustness of our design.     

光子晶体光纤分析及其在超连续谱中的应用

通过非线性效应,脉冲激光光谱可以大为扩展,得到应用价值很高的超连续谱（SC）,借助光子晶体光纤(PCF),能方便地产生这种非线性效应。研究了光子晶体光纤的包层等效折射率、归一化频率与PCF结构参数之间的关系,这是PCF实现无尽单模传输的原因。通过类似于阶跃折射率型光纤的理论,得到了光子晶体光纤的折射率和色散的计算模型。依据此模型所做的模拟结果表明,脉冲激光光谱有显著展宽。     

Highly nonlinear and highly birefringent dispersion compensating photonic crystal fiber

This paper presents an optimum design for highly birefringent hybrid photonic crystal fiber (HyPCF) based on a modified structure for broadband compensation covering the S, C, and L-communication bands i.e. wavelength ranging from 1460 to 1625 nm. The finite element method (FEM) with perfectly matched layer (PML) circular boundary is used to investigate the guiding property. It is demonstrated that it is possible to obtain broadband large negative dispersion, and dispersion coefficient varies from −388.72 to −723.1 ps nm⁻¹ km⁻¹ over S, C and L-bands with relative dispersion slope (RDS) matched to that of single mode fiber (SMF) of about 0.0036 nm⁻¹ at 1550 nm. According to simulation, a five-ring dispersion compensating hybrid cladding photonic crystal fiber (DC-HyPCF) is designed that simultaneously offers birefringence of order 3.79 × 10⁻², nonlinear coefficient of 40.1 W⁻¹ km⁻¹ at 1550 nm wavelength. In addition to this, effective area, residual dispersion, and confinement loss of the proposed DC-HyPCF are also reported and discussed.     

八角格子光子晶体光纤模式和色散特性研究

文章基于带有各向异性完全匹配层(PML)吸收边界条件的紧凑二维频域有限差分法对八角格子光子晶体光纤(O-PCF)的模式和色散特性进行了研究.利用有效面积法分析了八角格子和六角格子光子晶体光纤(H-PCF)的基模和多模截止特性,得到非限制模、基模及多模的相图,比较发现,填充率和空气孔间距相同时,O-PCF的单模运转区域宽于H-PCF,更易用于色散补偿.     

Novel design of highly nonlinear photonic crystal fibers with flattened dispersion

Novel highly nonlinear photonic crystal fibers(HN-PCFs) with flattened dispersion are proposed by omitting 19 air holes as the fiber core.The simulation results show that the high nonlinearity and the flattened dispersion can be achieved simultaneously by employing only two types of air holes in the cladding.To reduce the confinement loss,the modified designs are presented.The confinement loss is below 0.1 dB/km at 1.55 μm,when seven layers of air-hole rings are introduced to the cladding.After modifying,the dispersion can change from-0.5 ps/(nm.km) to+0.5 ps/(nm.km) in the range from 1.35 μm to 2.06 μm,and the effective mode area is as low as 2.27 μm 2 at 1.55 μm.     

大模场宽频单模光子晶体光纤的设计与制备

文章对无尽单模光子晶体光纤进行了理论设计,并提出了微结构光纤的制造工艺技术和相应的光纤拉丝工艺参数,制造出了较大模场的宽频单模光子晶体光纤,该光纤的芯直径为13.1 μm,微孔直径为3.2 μm,孔间距为8.2 μm,1 550 nm波长的模场直径为14.6 μm,1 550 nm的衰减为0.6 dB/km,1 383 nm水峰为14.9 dB/km.截止波长测试和近场光强分布检验表明,该光子晶体光纤确实具备较宽的单模工作范围.